Photoplethysmographic Diagnosis for Marginal Periodontitis

Research Project

Project/Area Number	62870075
Research Category	Grant-in-Aid for Developmental Scientific Research
Allocation Type	Single-year Grants
Research Field	Conservative dentistry
Research Institution	TOHOKU UNIVERSITY
Principal Investigator	HORIUCHI Hiroshi Tohoku Univ. Sch. of Dentistry, Professor, 歯学部, 教授 (00013962)
Co-Investigator(Kenkyū-buntansha)	YAMAKI Keiko Tohoku Univ. Sch. of Dentistry, Assistant, 歯学部, 助手 (90182419) IKAWA Motohide Tohoku Univ. Sch. of Dentistry, Assistant, 歯学部附属病院, 助手 (80176065)
Project Period (FY)	1987 – 1989
Project Status	Completed (Fiscal Year 1989)
Budget Amount *help	¥6,200,000 (Direct Cost: ¥6,200,000) Fiscal Year 1989: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000) Fiscal Year 1987: ¥5,300,000 (Direct Cost: ¥5,300,000)
Keywords	Photoplethysmograph / Gingival Blood Flow / Marginal Periodontitis
Research Abstract	Gingival inflammation accompanies disorder of local circulation. Therefore there exists a possibility for detecting inflammatory condition by observing gingival blood flow. The purpose of this study is to establish a method to record the photoplethysmographs from small gingival areas and to estimate gingival inflammatory stages by comparing the wave forms with those from normal area. Preliminary investigations were carried out to determine conditions for recording. A tungsten lamp connected to a stabilized power supply was used as the light source. A fiber optic bundle of 2 mm diameter was fixed to the adjacent tooth using an acrylic adapter. The bundle consisted of illuminating and recording fibers which were arranged randomly. A CdSe photoconductive cell was used as the photosensor. Simultaneous recording of the ECG was made and the recorded QRS spikes were used as the triggers for averaging the record. To record transilluminated plethysmographs, the outlet of the illuminating bundle was arranged lingually. In case of reflected photoplethysmographs, both the recording and illuminating fibers were placed tabially. When the bundle was placed close to the gingiva, dicrotic notches were cleatly observed both on transilluminated and reflected plethysmographs. Covering the surface of gingiva with white opaque paint resulted almost the same wave forms as transilluminated ones in reflected photoplethysmographs. To reject the 100 Hz noise from fluorescent lights at clinic, a sheet of aluminum foil was used around the recording site. Experiments were in progress to analyze the characteristics of photoplethysmographs recorded from inglamed gingiva and to relate the findings to other periodontal diagnostic parameters. The photoplethysmographs recorded from patients with marginal perjodontitis were smaller amplitude with less clear dicrotic notches than those recorded from normal gingiva.